Draft regulator



M. K. BRADY 2,133,803

DRAFT REGULATOR Filed May 6, 1937 //V V5 /V 7'01? Meme/L1. BRADY,

Patented Oct. 18, 1938 UNITED STATES DRAFT REGULATOR Merrill K. Brady, Kirkwood, N. J.

Application May 6, 1937, Serial No. 141,124

1 Claim.

As hereinafter described, my invention includes an annular frame in which a damper plate is pivotally' mounted so as to normally close an opening through said annular frame by gravitation of said plate, and the essential feature thereof is specific means including a weight which may be shifted in an arc of a circle with respect to the damper plate toward and away from the axis of the pivot of the plate to thus vary the gravitative effect of the weight upon the plate tending to close it in said frame.

. My invention is particularly applicable for controlling the influx of atmospheric air to a flue leading from an oil burning furnace to a chimney to admit more or less air to said flue in accordance with the fluctuations in natural convection draft of the flue and chimney. However, it is applicable to any other embodiment in Which it is desired to regulate fluid pressure or exhaust upon one side of the regulator by admission of fluid from the opposite side.

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

In said drawing: Fig. I is an elevation of a convenient embodiment of my invention inserted in a flue pipe.

Fig. II is a vertical sectional view of the structure shown in Fig. I taken on the line II, II, in the direction of the arrows in the latter figure.

Fig. III is an elevation of the inside of the regulator shown in Figs. I and II; the flue pipe shown in Figs. I and II being omitted.

In said figures; the annular frame I, which is conveniently formed of cast metal, is circular at its perimeter, which includes the rim flange 2 which abut-s against the end of the flue pipe 3, as shown in Fig. II. The perimeter of said annular frame I also includes the circular flange I, which as shown in Fig. II is slightly tapered inward with respect to said flue pipe 3, to facilitate the introduction of the annular frame into said pipe in the position shown in that figure.

In order to readily secure said annular frame I in said flue pipe 3, I find it convenient to provide the latter with the outwardly extending bead 3', conveniently formed by a rolling operation and to provide the flange 4 of said annular frame with three lugs respectively indicated at 5, 6, and 1, each respectively provided with set screws 5', 6, and I. Said set screws are re tracted when it is desired to introduce said annular frame I into the position shown in Fig. II

(Cl. 236-45) v by the screw 5 in Fig. II, to thus readily, rigidly I connect said annular frame I with said pipe 3.

The outer portion of said annular frame I is also inclined inwardly as indicated at 9 in Fig. II,

to facilitate the passage of'airthrough said annular frame I, to the interior of said pipe 3. Said annular frame I has the arcuate inwardly extending stopflange III at the lower portion thereof and the arcuate inwardly extending stop flange II at the upper portion thereof; said stop 10 flanges being in axially offset relation, as shown in Fig. II, to contact with opposite sides of the damper plate I3. Said plate is conveniently formed of thin pressed sheet metal having a cylindrical rim flange I3, to stiffen it. Said l5 plate is hung upon the pivot wire I4 which extends horizontally above the horizontal diameter of said plate I3, through opposite sides of said flange I3 on said plate and has its opposite ends respectively fitted in bearing lugs I5 projecting 20 from said annular frame I. Washers I6 are interposed between the inner circumference of said annular frame I and the flange I3 of said plate I3 to center the latter in the opening through said annular frame so that it is free to oscillate 25 upon said pivot wire I4 and normally gravitates into vertical position, shown in Fig. II. I find it convenient to provide the stop flange III with an inwardly extending lug I 0 to support the pad of resilient material I8 which is conveniently ce- 30 mented to said lug III to receive the impact of the lower edge of said plate I3 noiselessly.

Said pivot wire I 4 has the pendant bight I4 intermediate of its length to fit around the screw bolt I9 which extends through said plate I3 and 35 serves to prevent endwise movement of said wire I4, with respect to said annular frame I. Said bolt I9 has the handle head 20 permanently rigidly connected therewith; said head being conveniently formed of readily fusible metal, for in- 40 stance, aluminum, cast upon said bolt. The opposite end of said bolt I9 extends through the radial arm 22 of the weight 23 and is rigidly connected therewith by the nut I9. Said bolt I9,

which otherwise would be free for axial and ro- 45 tary movement with said weight .23 in said plate I3 is adapted to be readily fixed in different angular positions with respect to said plate I3, by means of the milled nut 24 engaged with said bolt I9 and bearing upon the washer 25 which en- 50 circles said bolt I9, in contact with the outer face of said plate I3.

It is to be understood that the arrangement above described permits said weight 23 to be readily manually adjusted, by the handle 20. in an 55 are with respect to said plate I3, from a position parallel with said pivot wire M, in which it has the least gravitative effect, to a position at right angles to said wire M, in which it has the greatest gravitative effect, to thus oppose more or less resistance to oscillatory displacement of said damper plate I3, from its normally closed position shown in Fig. II. Such adjustment is effected in accordance with the strength of the draft in the pipe 3 which is a branch of the flue pipe extending from the furnace to the chimney; so that the gravitative effect of said weight 23 upon the damper plate [3 may be increased in correspondence with increment in the force of the draft tending to open said damper plate I3 inwardly with re-' spect to the flue pipe 3 and thus regulate the effect of such draft upon the oil burner or other source of heat in the furnace to insure that the volume of atmospheric air drawn into the furnace by the draft in the flue shall be such as to effect satisfactory combustion of the fuel.

Although I find it convenient to secure my improved regulator in connection with the flue pipe by means of the set screws above described, engaging within the bead as shown in Fig. II; it may be secured by such screws in a flue pipe which is not provided with such a bead, and merely by pressure upon the inner cylindrical surface of the pipe. Moreover, any other convenient means for securing the regulator frame inthe desired position may be employed.

Therefore, I do not desire to limit myself to the precise details of construction and arrangement herein set forth as it is obvious that various modifications may be made therein without departing from the essential features of my invention as defined in the appended claim.

I claim:

In a draft regulator, the combination with an annular frame, of a substantially plane damper plate pivoted in said frame, above its center of gravity, and thus adapted to normally gravitate to position to close the opening of said frame; of a screw threaded member extending through said plate, intermediate of its width and approximately at the axis of its pivot in said frame, having at one end a radially extending handle outside of said plate and having at its other end a radially extending weight pendent at the inside of said plate; said screw threaded member and its appurtenances having freedom of movement for adjustment in an arc of a circle with respect to said plate; and a nut on said screw threaded member accessible from the outside of said plate; whereby, said weight may be adjusted from horizontal to vertical position to vary its gravitative effect upon said plate from miniumm to maximum and be temporarily rigidly secured in anyadjusted position, by said nut; the pivotal support for the damper plate comprising a wire extending horizonally above the center of gravity of said plate into bearings in said frame at its opposite ends, said wire having a 'bight intermediate of its length partly extending around said screw threaded member; whereby said member pre-' vents longitudinal displacement of said wire.

MERRILL K. BRADY. 

